Especially in the aircraft industry, it is becoming desirable that electronic control units, or "black boxes," each comprise a housing containing essentially a single circuit panel or mother board to which are electrically connectable a plurality of line replaceable modules on one surface and shipboard electrical systems on the other. Each line replaceable module, or LRM, performs a control or sensing or recording function and is itself essentially a circuit card or daughter board loaded with various electrical and electronic components. Such circuit card of choice evolves from very high speed integrated circuitry, or VHSIC, technology and is intended to be secured within a very durable, rugged, environmentally sealed metal housing. Therefore, for such a loaded circuit card to be contained entirely within a sealed housing an electrical connector is necessary to provide a means for electrically interfacing with a corresponding electrical connector mounted on the mother board. Such a daughter board connector must be secured to an edge of the daughter board (or plurality of daughter boards) at an end of the housing, and must itself be environmentally sealed about its electrical contacts and about its peripheral joint with the LRM housing. To be compatible with a densely packed VHSIC card or cards such a connector must have an array of contacts whose contact sections are engageable with closely spaced circuit paths of the cards, such as paths on 0.025 inch centerlines along an edge of the panel.
Such a high density connector for circuit paths spaced 0.050 or 0.025 inches apart is disclosed in U.S. patent application Ser. No. 06/930,587 now Pat. No. 4,715,829 wherein an array of contact terminals have long arcuate cantilever beam contact sections which are engaged with and electrically connected to the circuit paths of a panel. The terminals are secured in respective passageways of one of the connector housing modules and include box receptacle contact sections within portions of the passageways extending inwardly from a mating face for mating with corresponding pin contact sections of a mating connector. The housing includes a metal shell therearound for physical protection of the housing modules and also for protection from electromagnetic interference (EMI). The connector assembly is adapted to be mounted to a metal plate or heat sink on both sides of which are secured circuit cards bonded thereto by known heat conductive, heat resistant adhesive material, and which is inserted between pairs of mounting ears at opposite ends of the connector assembly; roll pins are then inserted through aligned bushings in each pair of ears and through the heat sink in a manner which allows the heat sink to float incrementally. While the cantilever contact beams of the first connector are arranged in two opposed rows and are spaced at 0.050 or 0.025 inches to correspond to the circuit path spacing on the surface of a respective circuit card, the box receptacle contact sections of the terminals are arranged in staggered fashion in four rows to accommodate the size of the box receptacle contact sections; the box receptacle contact section is disclosed in U.S. Pat. No. 3,404,367. The mating connector includes pin contact terminals which have pin contact sections extending outwardly from one face of a housing within a metal shroud of the connector and are matable with the respective box receptacle contact sections of the first connector. The pin contact terminals have pin contact sections extending outwardly from the connector housing on the other side, to be inserted into holes of a printed circuit board or the like and electrically connected thereto, which holes may have a different pattern and spacing than the pattern and spacing of the contact sections of the mating pairs of terminals of the mating connectors. The mating connectors also have keying and polarizing features.
It is desirable to provide a mating connector assembly for electrically interconnecting circuit cards having circuit paths on 0.025 inch centerlines, to a mother board having circuit means on like or different spacing and pattern.
It is also desirable to provide a connector for an LRM which is firmly secured thereto in a manner which includes means for sealing engagement between the dielectric housing means of the connector and the metal cover means thereof, where the housing means is adapted to float incrementally therewithin in a transverse direction with respect to the connector mating face.
It is further desirable to provide such an LRM connector with means to seal environmentally around the contact sections of its terminals which are exposed to be electrically engaged by corresponding contact sections of terminals of a mating connector.
It is further desirable to provide means for aligning the LRM connector incrementally into an accurate orientation with respect to the mating connector fixed in position on a mother board for the arrays of corresponding pairs of contact sections of the two connectors to mate, while the LRM itself is not incrementally alignable.
It is yet further desirable for the connector assembly to provide means for transmitting electrical power from a power source into the LRM to provide power, for instance, to components assembled to the circuit cards within the LRM assembly, to provide means for coaxial signal transmission, and to provide means for transmitting optical signals into and out from the LRM assembly.
It is still further desirable to provide a mother board connector assembly matable with the LRM connector and providing for power, coaxial signal and optical signal interconnection with the LRM assembly, and which includes a metal shroud therearound grounded to the mother board and together with appropriate grounding engagement with the metal housing of the LRM assembly provides EMI and ESD shielding of the entire interconnection between the LRM assembly with the mother board connector.
It is desirable to provide a method for securing contact sections of an LRM connector to surface contact sections of VHSIC circuit cards within the LRM assembly on close spacing such as on centers spaced 0.025 inches apart, without requiring tooling for alignment of the contact sections of the connector individually with the corresponding circuit card contact sections prior to joining the corresponding contact sections together in a secure mechanical and electrical connection.
It is also desirable, within both the interior of the LRM assembly and the interior of a corresponding black box into which it is to be removably inserted for in-service use, to provide for power, coaxial and optical fiber cable means to extend from the LRM connector assembly and mother board connector assembly respectively.